Synthesis of novel guanidine-based ABA triblock copolymers and their antimicrobial honeycomb films

Novel amphiphilic poly(methacryl guanidine hydrochloride)-block-polystyrene-block-poly(methacryl guanidine hydrochloride) (PMAGH-b-PS-b-PMAGH) ABA triblock copolymers with a controlled molecular weight and composition were synthesized via sequential reversible addition/fragmentation chain transfer (RAFT) polymerization of methacryl guanidine hydrochloride (MAGH) and styrene, using S,S′-bis (α,α′-dimethyl-α′′-acetic acid) trithiocarbonate (BDATC) as the initial chain transfer agent. Highly ordered honeycomb films of PMAGH-b-PS-b-PMAGH were fabricated via a facile and versatile static breath-figure process. PMAGHs and the honeycomb films of PMAGH-b-PS-b-PMAGH showed high antimicrobial activity against Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis). The minimum MIC values of PMAGHs are 113 μg mL−1 for E.coli and 450 μg mL−1 for B. subtilis. PMAGH-b-PS-b-PMAGH honeycomb films inhibited 61% of E. coli and 92% of B. subtilis.